Recently, as next-generation energy, various fuel cell modules and fuel cell devices that contain such fuel cell modules inside exterior cases have been proposed. In such fuel cell modules, a plurality of fuel cells that can generate power using hydrogen-containing gas (fuel gas) and air (oxygen-containing gas) are arranged with a current collector being disposed therebetween and are electrically connected to form a cell stack, and such a cell stack is fixed to a manifold for supplying fuel gas to the fuel cells, thus constituting a cell stack device, and such a cell stack device is housed inside a housing (see, for example, Patent Literature 1).
In such a fuel cell device, to supply the required power that is required by a load, the flow rate of the fuel gas supplied to the fuel cells, the voltage of the fuel cells, and the like are suitably adjusted.